PSY290H5 Lecture Notes - Lecture 4: Potassium Channel, Axon Hillock, Electrochemical Gradient
Document Summary
The distribution of ions inside and outside of a neuron. Sodium much more heavily concentrated outside than inside of the cell (same w/ chloride) Ionic basis of resting potential: the resting potential is neg because of the na+/k+ pump. Carries out sodium ions (3 na+ out) and brings in potassium ions (2 k+ in) What makes action potential or activity of a neuron possible. Integration of postsynaptic potentials and generation of action potentials. Action potentials are generated at the initial axon segment. Things that are in the axon that aren"t in anywhere else of a neuron. Very special channel not really found in any major quantities outside of an axon. 2 principle types of these channels relevant to action potentials: First sight/origin of all action potentials are at initial axonal segment. Axon hillock --> transition zone --> no voltage-gate channels here. First place in neuron that initially responds to electrochemical gradient: the voltage gated sodium channel.
